Impact-fuse



E J. W. RAGSDALE.

IMPACT FUSE.

APPLICATION FILED JULY 30.1918.

1,375,66 Patented Apr. 19 1921.,

2 SHEETS-SHEET I.

24 I yumm E. J. W. RAGSDALE.

IMPACT FUSE.

APPLICATION FILED JULY 30. 1918.

Patented Apr. 19, 1921.

2 SHEETS-SHEET 2.

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III

EARL J'. W. RAGSDALE, OF THE UNITED STATES ARMY, ASSIGNOR TO SECRETARYOF T WAR, TRUSTEE FOR GOVERNMENT OF UNITED STATES OF AMERICA.

IMFACT-FU'SE.

Specification of Letters I atent.

Patented Apr. 19, 1921.

Application filed July 30, 1918. Serial No. 247,381.

To all whom it may concern. 4

Be it known that I, EARL J. W. RAGS- DALE, Lieut. Colonel, OrdnanceDepartment, United States Army, a citizen of the United States,stationed at Washington, D. C., in the office of the Chief of Ordnance,have invented an Improvement in Impact-Fuses, of which the following isa specification.

The invention described herein may be used by the Government, or any ofits oflicers or employees in prosecution of work for the Government, orby any other person in the United States, without the payment of anyroyalty thereon. 4

This invention relates to an improvement in impact fuses for projectileswith special reference to the type thrown from trench mortars.

Experience has shown that the percentage of failures among the trenchmortar proj ectiles is very high and these failures are in manyinstances due to the premature ex-' plosion of the projectile. Thisinvention therefore deals with an arrangement whereby the detonation ofthe fuse is retarded, and, more specifically, with a retardingarrangement for that type of fuse wherein the safety holding pin or forkis moved out of engagement with the firing means.

According to the present invention the safety fork is arranged andformed so as to retard the action of the actuating spring duringacceleration so that the projectile will be entirely out of and clear ofthe gun before the fork is disengaged.

In the embodiment illustrated in the drawings the invention comprises anupturned or beveled surface rovided on the end of the fork, which surace during acceleration frictionally bears against the shoulder of thestriker when the ejecting spring is functioning to retard its action inthrowing out the fork. Though other embodiments of the invention arepossible, the'above form is illustrated in the accompanying drawingswherein:

Figure l is a transverse section of a fuse taken on the axis of theprojectile showlng the parts in normal safety position;

' Fig. 2 is a like view showlng the set-back pellet in unlockingposition, and the functioning of the retarding arrangement;

Fig. 3 is a like view, but showing the parts sleeve.

at the instant of lateral impact with the fork ejected, and the set-backpellet closing the opening through which it is ejected;

Fig. 4 is an elevation showing the safety pin in position;

Fig. 5 is a section of the safety fork taken on the axis of the fusewhen the parts are' in normal position;

Fig. 6 is an end view of the fork taken when the parts are as shown inFig. 2

Figs. 7, 8 and 9 are perspective views of the safety fork and of thesleeve and striker and firing mechanism respectively.

The fuse comprises a hollow, cone-shaped body 1, adapted to be screwedinto a threaded recess formed in the nose of a projectile. The point ofthe fuse consists of a cone cap 2 screwed into a suitablythreadedopening of the body 1. The cap forms a closure for themainchamber 3 and is coned upon its inner surface. An axially arrangedpowder chamber 4 is separated from chamber 3 by the seat 5 coned on itsside toward chamber 3. The inner end of the powder chamber is normallyclosed by the plug 6.

' The detonating or firing mechanism comprises a striker shown in detailin Fig. 9 and the sleeve shown in detail in Fig. 8. The striker isprovided with a round head 7, a cylindrical stem 8 and a fixed firingpin 9. The stem 8 extends into one end of a cylindrical sleeve 10 andslides freely therein. The other end of the sleeve carries a percussioncap or primer 11 in alinement with the pin 9 of the striker. The sleeveand the striker are held apart by a light spring 12 surrounding the stem8, and bearing with one end against the head 7 of the striker and I atits other end against a shoulder on the The end of the sleeve carryingthe primer is of a frusto-conical shape and seats in the coned surfaceof member 5, while the rounded head 7 of the striker normally bearsagainst the coned inner surface of the cap 2.

Lateral to, but parallel with, the axis of the fuse is a cylindricalbore or chamber 13, the inner end of which is closed by the plug 14.This bore houses the set-back pellet 15 and the spring 16. The pellet isprovided at its forward end with a lug or pin 17 which, due to thecompression of the spring 16 between the plug 14 and the inner end ofthe pellet, locks the safetyholding fork or pin. The safety fork ishollow and has a body 18 and a head 19. The inner end of the pin has alongitudinal slot cutinto one side about one-half the distance of itslength so as to form a trough 20, as clearly shown in Fig. 7. The fork,due to its trough-like shape, constitutes a safety arrangement forpreventing the pin 9 of the striker from contacting with the cap 11, dueto impact along the axial line of the fuse, until the fork is movedentirely out of contact with the striker. The edges of the trough 20 areeach provided with a beveled surface 21 at the extreme inner end of thefork. The purpose of this bevel will be explained hereafter.

The safety fork is housed in a transversely extending bore 22 connectingthe chambers 3-and 13 just in front of the seat 5. The enlargement 23 ofthe bore 22 in the outer wall of the body 1 provides a shoulder in theborebetween which shoulder and head 19 of the fork there is held theactuating or ejecting spring 24, normally urging the pin outwardly. Thesleeve 10 of the firing mechanism is provided with a transverse opening25 through which the trough-like end 20 of the safety fork extends. Thepin 17 of the set-back pellet locks the fork in safety position byextending through holes 26 provided in the fork.

A safety pin 29 is providedto positively secure the parts in safetyposition during transportation. The pellet 15' is provided with anopening 27 which alines with openings 28 in the body of the fuse whenthe parts are in position as shown in Fig. 1, thereby permitting theready insertion and withdrawal of the safety pin. This pin is of theusual split cotter-pin type and is withdrawn by means of ring 30 justprior to the loading of the projectile into the gun.

The operation is as follows:

The safety pin having been withdrawn be-' fore loading so that theset-back pellet 15 will function, the parts are as shown in Fig. 1, withthe pin 9 of the striker in the trough of the fork. The firing of thegun will cause that pellet to compress the spring 16 owing to set-backor inertia, and consequently the pin 17, disengaging from thesafety'fork, leaves the latter free to be ejected under action of thespring 24. The safety fork is thrown out from the fuse only after theprojectile has left the gun and is well clear of the same, due to theretarding action of the beveled surfaces 21 of the fork. From Fig. 2 itwill be noticed that as the spring 24 is functioning, and duringacceleration, the surfaces 21 of the fork, due to their wedging actionin cooperation with the lower end of the cylinder 8 of the striker,retard the movement of the safety fork until the projectile is fullyclear of the gun or mortar, for, as long as the projectile is beingaccelerated, the striker is exerting a rearward pressure, in thedirection indicated by the arrow in F ig'. 2, against the edges of thetrough.

The fuse is adapted to function on im pact, no matter in what direction,head-on, base-on, or laterally, the same may take place. In case ofeither head-on or base-on impact, the action is clear, the striker andsleeve merely coming together, compressing the spring 12, and the pin 9puncturing the cap 11. In case of lateral impact, for instance, as shownin Fig. 3, the two cone-like surfaces at the inside of cap 2 and of seat5 cause a camming action of the striker and sleeve respectively, tosimilarly operate the detonating mechanism.

As further shown in Fig. 3, after the safety holding fork has been fullyejected, the spring 16 moves the pellet 15 forward so that it acts as ashutter and closes up the opening in the body of the fuse through whichthe fork has been ejected, thus preventing mud and dirt from enteringthe fuse on impact and impairing the operation of the same.

From the foregoing description it will be noted that none of the partsof the fuse depends on the action of centrifugal force. Further, thatthe retarding arrangement is due to friction and inertia, functioning aslong as and only while the projectile is being accelerated, and issimple and positive in action, thus insuring safety to the operators ofthe gun or mortar and greater assurance that the fuse will properlyfunction.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a fuse for projectiles, the combination of a fuse body providedwith an opening; firing mechanism in the body; combined holding andretarding means for retaining said mechanism in safe condition duringacceleration; and means for ejecting said combined means through saidopening.

2. In a fuse for projectiles, the combinaof a hollow body having anopening in the wall thereof; firing mechanism in the body functioning onimpact in any direction; combined holding and retarding means forretaining the mechanism in safe condition during aceleration; and meansfor ejecting said combined means through said opening.

3. A fuse for projectiles comprising in combination, firing mechanismadapted to function on impact in any direction, a safety device forholding said mechanism in safe condition movable through an opening inthe wall of the fuse, means to eject said 12 safety device, and lockingmeans of the setback type for retaining said safety device normally inplace, and retarding means for preventing the premature ejectment of thesafety device.

4. A fuse for projectiles comprising a body provided with 'a chamberhaving an opening in the wall thereof; firing mechanism in the chamberadapted to flmctionon impact in any direction and including twotelescoping elements, one of which elements has an opening alined withthat in the body; a device situated in the alined openings for holdingthe mechanism in safe condition;

means for withdrawing and ejecting the safety device from the fuse; andcombined locking means for the. safety device and closing means for theopening in the body.

5. In a fuse for projectiles, the combination of a fuse body providedwith an opening; firing mechanism in the body functioning on impact inany direction and consisting of a striker and sleeve, said sleeve beingalso provided with an opening; asafety fork for the firing mechanismextending in line with the openings in the sleeve and body I throughwhich the fork may be introduced, a spring acting to withdraw and ejectthe fork through the opening in the fuse body; a combined lock andshutter; and

a spring urging the lock and shutter into opening in the wall thereof,and the endwalls whereof are reversely coned; a sleeve having a conedend. bearing against one of the coned ends of the chamber, and providedwith a lateral opening; a detonating cap carried by the sleeve; astriker compris' a head, stem, and firing pin; the stem of the strikersildable in the sleeve and the pin being in alinement with the cap; alaterally extending device situated in the openings in the sleeve andfuse body for holding the parts in safecondition; means for withdrawingand ejecting the safety device from the fuse; and means for retardingthe action of the ejecting means during acceleration comprising aninclined surface on the end of the safety device and the stem of thestriker.

. EARL J. W. RAGSDALE.

cooperating with

